Apparatus for the production of music



1939- c. T. JACOBS APPARATUS FOR THE PRODUCTION OF MUSIC Filed April 23, 1937 3 Sheets-Sheet 1 July 11, 1939 c. T. JACOBS APPARATUS FOR THE PRODUCTION OF MUSIC 3 Shets-Sheet 2 Filed April 23, 1957 v 4/ wk ll M July 11, 1939. c. T. JACOBS APPARATUS FOR THE PRODUCTION OF MUSIC Filed April 23, 1957 3 Sheets-Sheet 3 m a 2 i f l III: M w r+ r i I H m n 1 2% r 3 4 I I I a w. :11 C m. I a t |||fi t i m c w a I la a a i m a a a 4 0' Z M a a 3 3 a E v 2 m l a HE 1. l a c llfl 3 2 5 m a /v .0 J M m ,4J 7

Patented July 11, 1938 UNITED STATES PATENT OFFICE Charles '1. Jacobs, New Providence Township,

Union County, N. 1., assignor to Miessncr Inventions, Inc., Millburn, N. J., a corporation of New Jersey Application April 23, 1937, Serial No. 138,582

19 Claim.

This invention relates to the production of music, and more particularly to that production from a plurality of continuously operating generators, these producing electric oscillations and these oscillations being translated, after suitable amplification, into output tones.

It is an object of my invention to provide improved means, method and instruments for such production.

It is an object to provide simplified means,"

methods and instruments for such production.

It is another object to provide improved or simplified arrangements of the generators and their output means in such instruments.

It is another object to provide in such instruments improved or simplified arrangements of the generators, with their output means, and the keying means. 7

It is another object to provide advantageous groupings of the output means of the generators 1 simplified arrangements of a plurality of capacitative generators with their output electrodes in such an instrument.

Still another object is the provision of an advantageous plural-electrode unit for employment in such generators.

It is still another object to simplify the control of the tone attack" and release ininstruments of the class described which are adapted for very complete output tone quality control.

Other and allied objects will more fully appear from the following description and the appended claims.

In the description hereinafter set forth reference is had to the accompanying drawings, of which:

Figure 1 is a generally elevational view of a portion of a plurality of generators for an instrument according to my invention, certain of the components of the figure being schematically shown;

Figure la is a fractional view, intended for optional substitution for a corresponding portion of Figure 1, illustrating an optional modification of a portion of each of the generators;

Figure 2 is a vertical cross-sectional view taken along the line 2-4 of Figure 1 and illustrating the simultaneous use of a plurality of the output 5 electrode units one of which appears in Figure 1, the line l-l of Figure 2 indicating the relationship of Figure l thereto; and

Figures 3 and 3a together comprise a partially plan but largely schematic view of an instrument 10 wherein my invention h been incorporated, the showing having been plificd to some extent in the interest of readability of the drawings: Figure 30 comprises the central portion of the showing, intended for insertion between the portions of F Figure 3 respectively to the right and to the left of the line Iii-3a.

My invention involves the use, itself well known, of a plurality of continuously operating generators, for example one for each note of a musical scale-each generator with appropriate output means operative, for example, when sensitized (as by an electric voltage or current) under the selective control of the playing keys. According to one aspect of the'invention, however, I employ in the sensitizing means therefor a plurality of conductors (for example, one per note) each arranged for the sensitization in common of a group of output devices-each such group comprising, for example, an output device on each of a plurality of generators harmonically'related in frequency. I may make the devices of each such group peculiar to the conductor therefor, or distinct from those of any other such group, for that purpose employing for each of at least a large number of the generators a plurality of output devices.

According to another aspect of the invention, I group the output devices for combination of the outputs from devices for generators of consecu- 40 tive notes, and I otherwise group the output devices for simultaneous sensitization of devices for generators of harmonically related notes; the first-'mentioned grouping may be in manner to facilitate the control of quality (e. g., harmonic 4 structure) of the output tones. I may make both these distinct groupings permanent. Again, .I may make them of mutually distinct nature-for example, one a conductive grouping and the other a reactive grouping.

These, and other broad and more limited aspects of the invention, are illustrated and are hereinafter described, with attention to many of their advantages. Purely typically, the illustration and description is of an instrument having I individual generators in the form of individual sound tracks, with pick-ups therefor forming the output devices. According to broader aspects, the pick-ups may operate on any known principle, with thereto appropriate form of track and pickup; but I have particularly illustrated herein, by way of example, a capacitative pick-up action, and track and pick-up electrode appropriate thereto. While the formation of the track to cause a required periodic capacity variation may be as desired, I have specifically shown a variable-area formation. The sensitization of a capacitative pick-up will be understood to involve the impression, across the periodically varying capac1ty, of a voltage of inaudible frequency-typically of zero frequency, or direct voltage, which I have specifically shown by way of example only.

Figure 1 fractionally illustrates two tracks, I

' and 2, carried by a cylinder 3; the cylinder is suitably journalled for rotation, as indicated as to its left-hand end by the thrust of its inwardly-coned shaft 4 against a conical bearing 5 in standard 6, and by the driven gear 32 secured on the shaft. Each track may encircle the cylinder 3, and may be in the form of a conductive strip of contour representing a desired wave form-for example, a sinusoidal one. The cylinder surface is arranged to have an electrostatic influence on the adjacent pick-up electrodes (hereinafter described) which is minor relative to that of the tracks, and accordingly the tracks may be appreciably raised above the surface of the cylinder, or at least the outer portion of the cylinder maybe of insulating material, or both; if the cylinder is of insulating material, spring brushes schematically illustrated as I and 8, contacting the tracks, may for example be employed to effect the electrical connection of the tracks to the metallic standard 6 which would otherwise be effected through the cylinder and its shaft 4 and bearing 5. As hereinafter appears, a plurality of cylinders may be employed, each carrying a number of tracks harmonically related to each other in frequency; a useful arrangement is that of l2 cylinders each carrying tracks of corresponding notes in all octaves of the range of the instrument (and desirably in one or more still higher octaves for harmonic development, as hereinafter more fully appears). For the several tracks of each cylinder I have illustrated a plurality of respective pick-up electrodes held together in a unit l0 which may now be described, but some of whose particular advantages will be more apparent hereinafter; in connection with the unit ID reference may also be had to the crosssectional Figure 2, in which in cross-section appear a plurality of these units-for the abovementioned provision of a plurality of output devices (e. g., electrodes) per generator (e. g., track).

Each unit l0 may be formed of two metal strips H and I2, roughly as long as the cylinder 3, and clamped together as by screws 9 opposite spaces between the tracks. Intermediate of the screws there may be clamped between the strips H and 12 pairs of thin mica or other dielectric sheets l3 and II (for example of only a few thousandths of an inch thick) these may extend slightly beyond the edges of the strips l l and 12. In turn between each pair of dielectric sheets l3 and I4 may be clamped a thin metal sheet l5 having a main por tion of slightly smaller area than the dielectric sheets, but having a small tab l6 extending therebeyond on one side for electrical connection purposes, and having a larger extension l'l beyond the dielectric sheets on the other side. To each tab I6 is shown connected a small respective resistor l8, which may typically be of several or many megohms resistance.

The several extensions l1 form pick-up electrodes for the several tracks; accordingly each unit l0 may be supported longitudinally of the strips; this extension in turn may be rigidly secured, as to standard 6, through a bracket 20. For

adjustment of the ends of the unit, to bring the electrodes ll into desired close spaced relationships with their respective tracks, I have shown the securing of the bracket 20 to standard 6 as effected through the medium of a threaded stud 2| projecting from the standard, and nut 22 and thumb screw 23 on the stud respectively above and below the base of the bracket.

It is convenient hereinafter to consider the potential of the standard 6, and therefore of the tracks, as a reference or ground potential, for which reason the standard 6 has been shown connected to ground in Figure 1.

In Figure 1 I have included a simplified schematic showing of circuit arrangements for the sensitization of the electrodes I! and for the utilization of their outputs. The upper end of each resistor i8-and, through tab l6 and that resistor, the respective electrode l|may be connected to the pole of a respective double-throw switching means 24; by this switching means (e. g., when this is upwardly thrown) it may normally be rendered at ground potential. But upon downward throwing of the respective pole, a pick-up electrode will be connected (of course, still through resistor l8) to the non-ground terminal of a source 25 of the inaudible-frequency voltage abovementioned. No limitation as to the nature of the switching means is intended in broader aspects, as it is only necessary that these means be of a form appropriate to the nature of the voltage from source 25.

Accordingly by the several switching means the sensitizing voltage is applied selectively across the periodically varying capacities from electrodes I 1 to the respective tracks (it being assumed, of course, that the cylinder is being continuously rotated); and when that voltage is so applied across any of these capacities, the respective electrode I! will develop a potential difference from ground which varies in accordance with the frequency and waveform of the respective track. The strips lll2 may be connected to ground through a very high impedance load typified by the resistor 26; and by virtue of the capacities from each electrode to those stripsi. e., from the metal sheets I5 through the dielectric sheets l3-|4-there will appear across the load a voltage representing a superposition of potentials developed on all the electrodes [1. The load 26 may for example be the input circuit of a repeater tube 21, shown in Figure 1 with by-passed self-bias resistor 28 and plate voltage source 29. It will be understood that in the particular case of a direct voltage from source 25, tube 21 would be operated as a simple amplifier; while in the case of other inaudible-frequency voltage from the source 25, tube 21 would be operated as a demodulator.

- The electrodes, when taken as including the integral sheets 15, will be observed to be at once portions of the periodically varying capacities, and plates of fixed condensers for transferring oscillations from those varying capacities-the other plates of those fixed condensers being the strips ll--|2. In Figure l I have schematically indicated as 30 grounded electrostatic shielding surrounding the unit I0, excepting for its side disposed toward the cylinder and tracks and for the insulating mounting extension l9; and as 3| grounded electrostatic shielding disposed about the lead from the strips ll-li and the load 26, etc. In Figure 2, wherein a plurality of units Ill appear, I have schematically shown the shielding 30 not only as surrounding each unit but also as isolating the several units from each other. Typically the connections from the top extremities of the several resistors may individually pass insulatedly through the shielding 30.

The unit l0 broadly represents a grouping together (e. g. capacitatively) of a plurality of output devices (e. g., electrodes) for combination of their outputs, yet with the devices otherwise (e. g., conductively) independent for selective control of their sensitizations-making possible the construction of a very simple and fiexible instrument as next typically described. At the same time the unit more specifically is a very simple and economical arrangement for the provision of a plurality of capacitative ly coupled electrodes.

In Figures 3 and 311 I show an arrangement of a plurality of the assemblies of Figures 1 and 2 in a musical instrument which, purely by way of convenient example, may be assumed to have four octaves-4mm C1! to C, C3" to C, Ct to C and Ci" to C" consecutively in ascending direction. Four of the cylinders of the instrument (which may for example total the 12 abovementioned) appear as E, F, B and C. Cylinder E may carry tracks E1, E2, E3 and E4 for the production of the E5 in the four respective octaves of the instrument; and two additional tracks E5 and E6 for the production of two consecutively still higher Es. Quite correspondingly cylinder F may carry, for the production of corresponding Fs, six tracks F1 through Fe; and, again correspondingly, cylinders B and C may carry six tracks each-B1 through Bo, and C1 through Co, for production of B's and Cs. The gears 32 of the several cylinders are shown engaging other gear means 33 by which they are jointly driven in suitable speed relationships-it being understood that no limitation to similarity of any of these gears or gear means or to singleness of each of the latter is intended, but rather that they will be suitably chosen and related to provide a substantially equally-tempered scale, in manner well understood in the art.

Above the cylinder E there will be seen five of the units ID, the shielding I0 therefor having been omitted from the drawing for the sake of simplification. The most forward (or bottomshown) of these units may comprise four output means or electrodes, for providing the fundamental components for the respective four Es of the instrument; such four electrodes, each in combination with its respective resistor l8 have been indicated as E1, E21, E31 and E41 respectively, above tracks E1 through E4 consecutively. The next or second of these units may comprise four output means or electrodes, for providing the second partial components for the respective Es of the instrument; its four electrode-resistor combinations have been indicated as E22, E32, E41

and E52 respectively, above tracks E: through E5 consecutively. The third of these units may comprise four output means or electrodes, for providing the third partial components for the respective As of the instrument; its four electrode-resistorcombinations have been indicated as E34, E44, E54 and E64 respectively, above tracks Ea through Ea consecutively. The fourth unit may comprise four output means or electrodes, for providing fourth partial components for the respective Es of the instrument; its four electrode-resistor combinations have been indicated as E14, E44, E54 and E64 respectively, above tracks E3 through Ea consecutively. The fifth or last-.

shown unit may comprise three output means or electrodes, for providing the sixth partial components for the respective As of the instrument (excepting, by way of example, the top A); its three electrode-resistor combinations have been indicated as E46, E56 and E641 respectively, above tracks E4 through Es consecutively. It will be observed that in the designation the letter and first digit of the subscript has been chosen to indicate in each case the track over which'the electrode ,lies, and the second subscript digit to indicate the order of the partial component for which it is employed.

Above cylinder F five corresponding units l0 may be employed. In the interest of simplicity they have been only fractionally illustrated; but all the electrode-resistor combinations have been shown. These have been shown arranged and designated entirely similarly to those for cylinder E, except for the change of letter to F; and itwill be understood that their functions are quite correspondent with ,those stated above, excepting that E will be read as F, and A as Ail. Above each of cylinders B and C five again corresponding units may be employed, and have been illustrated and their electrode-resistor combinations designated quite correspondingly to those for cylinder Fexcepting, because of these notes lying among the top five of the basic octave Ct to C, that the four electrode-resistor combinations for the third partial component (e. g., Fax,

by the four B36, B48, B56, B66 0r Cae, C40, C55, C66.

And it will be understood that for each of the balance of the 12 cylinders of the instrument five units ID will be employed, arranged as are those actually shown (in the case of those for other of the bottom seven notes of the basic octave, 0

like those for cylinders E and F; and in the case of those for other of the top five notes of the octave, like those for cylinders 13 and C) All the electrodes for producing fundamental components are permanently grouped together; it will be appreciated that this condition already exists capacitativelyas to those associated with any one cylinder (e. g., as to E11, E21, E31 and E41) by reason of their joint presence in a single one of the units I0, and it is readily extended to the entire instrument by connection of all the fundamental units (i. e., of their strips ll-l2) to a common conductor 4|. Likewise all the electrodes for producing second partial components are permanently grouped together by connection of their respective units to conductor .42; all the electrodes for producing third partial components, by connection of their respective partial components, by connection of their respective units to conductor 44; and all for producing sixth partial components, by connection of their respective units to conductor 46.

The potentials on these conductors are combined-preferably following a selective control of each, and if desired following individual passages through respective repeater tubes. Accordingly in Figure 3a I have shown these conductors connected through the respective high resistances GI, 62, 63, 64 and 66 to ground, and respective repeater tubes 1|, I2, I3, 14 and 16 of which these respective resistances form the input circuits; if.

desired, condensers 5|, 52, 53, 54 and 56 may be interposed between the respective conductors and high resistances. In the output circuits of the repeater tubes have been shown respectively connected the primaries of transformers 8|, 82, 83, 84 and 86, across the secondaries of which appear the respective potentiometers 9|, 92, 93, 94 and 96. A variable portion of each potentiometer may be connected in a commonfor example, a series-circuit, which may typically feed into a cascade of amplifier 91, potentiometer or volume control 98 (manipulated as by pedal 98a) further amplifier 99, and loudspeaker Hill, for amplification, general amplitude control, and translation into output tones of the superposed potentials from the several output devices or electrodes.

It will be understood that by variation of the variable portions of the several potentiometers there may be exerted full control of the contributions of the fundamental, second partial, third partial, fourth partial and sixth partial output means or electrodes to the output tones. If the tracks are purely sinusoidal, an amplitude control only need be exerted by each potentiometer; but if, as I have fractionally illustrated by tracks la and 2a in the alternative Figure 1a, each track be made to represent not only its main or above described frequency but also one or more harmonics thereof, phase as well as amplitude may advantageously be varied by the potentiometers. Accordingly I have illustrated the variable portion of each as that portion which lies between a fixed center-tap (e. g., 9|c, 920, etc.) and a contact (e. g., 9 41, 92a, etc.) referably fully variable over the whole potentiometer resistance.

Shielding 3|, for each of the conductors 4|, 42 etc. and the associated condensers SI, 52, etc., the associated high resistances GI, 62, etc., and the associated repeater tubes 1|, I2, etc., has been schematically indicated in Figures 3 and 3a.

The reactive grouping of the output devices and its usefulness for tone quality variation pur-, poses having been so described, attention may be directed to the distinct groupingfor example, conductiveof those devices for appropriate simultaneous sensitizations. Among the output devices or electrodes which I have described there will be found an individual one for each of the first (fundamental), second, third, fourth and sixth partials of each note of the instrument (excepting only for the sixth partials of the top seven notes); and (subject to that unimportant exception) I group together, for each note, individual output devices for those five partials thereof so that the same may be simultaneously sensitized. This I may do permanently, and conductively; and I have indicated this in full for all the Es and all the F's of the instrument. Thus there may be grouped conductively by conductor e, and connected to the pole of a switching means 24 (as in Figure 1) responsive to the key E, the electrode-resistor combinations E11,

the top extremities of the respective resistors)- these combinations being those for the first, secand, fourth, third and-sixth partials respectively of the note E. There may be correspondingly grouped conductively by conductor j, and connected to the pole of like switching means responsive to the key F, the electrode-resistor combinations F11, F22, F34, C23 and Can. Entirely corresponding groupings, displaced upwardly by an octave (e. g., by one track on each of the respective cylinders) have been illustrated for E" and F", with conductors e" and j"; displaced upwardly by two octaves, for E' and F, with conductors e and f; and displaced upwardly by three octaves, for E"" and F"", with conductors e"" and j"".

Each switching means is of course arranged normally to ground the respective conductor; upon key depression to connect it with the ungrounded terminal of source 25, as in Figure 1; and upon key release to restore it to ground potential. It will accordingly be understood that upon depression of the key for any note, the electrodes or output means peculiar to the several mentioned partials of that note will be simultaneously sensitized; and all those partials will combinedly appear as an output tone, subject to the individual regulation of each (in common for all notes) by the respective one of the potentiometers 9|, Q2, etc. The effects produced upon simultaneous depression of a plurality of keys will of course be understood to be simply the superposition of the effects produced by those keys individually or a simultaneous prdduction of a respective plurality of output tones.

When a direct potential source with conductive switching means is employed it may be desirable to render finite the rates of potential change of the respective electrodes, and hence the tone attack. and release. This may readily be done by associating with each grouping means last mentioned-e. g., by insertion in each of the respective conductors e, f, etc.-a time-delay means such as the two-stage series-resistance, grounded-shunt-capacity network which I have illustrated as |0| in [each of the illustrated conductors. The use of such means broadly is of course well known; but my invention provides the particularly simple arrangement of only one of these means per note, yet in an instrument wherein full individual control may be exerted over each discrete partial component of the output tones.

In Figure 3 the groupings for simultaneous sensitization of the output means for notes other than the Es and the F's have been only incompletely shown in the interest of simplicity of the drawing; but the details of these groupings, in analogy to those described, will be quite obvious to those skilled in the art. And it is distinctly to be understood that by the specific mention of a particular five partial components only I intend no limitation to those particular five, as the manner of extending my invention to embrace any and all partial components up to the tenth or higher will likewise be utterly obvious. Details such as the arrangement of the cylinders, the range of the instrument in octaves, the nature of the combining and control means for the several partial outputs, the use or omission of in-- dividual repeater tubes or amplifying means for each partial component before combination, and the like are of course matters of choice in any given case.

E22, E54, B2: and B30 (of course by connection to And even in broader aspects the particular in- 16 strument which I have illustrated and above detailedly described is typical only and by no means exhaustive of arrangements for carrying outmy invention, and I intend thereby no limitation of the scope of the latter; rather in the appended claims I undertake to express that scope broadly, limited only by the state of the art.

I claim:

1. In a musical instrument having a plurality of generators of frequencies respectively representing a. musical scale, means for continuously operating said generators, and an electro-acoustic translating device: signal-transmitting means permanently connecting said generators with said translating device; output devices included in said generators, said transmitting means being responsive to said generators in accordance with sensitization of said output devices; and means for selectively sensitizing said output devices, including a plurality of conductors each for the sensitization in common of output devices for a plurality of different generators.

2. In a musical instrument having a plurality of generators of frequencies respectively representing a musical scale, means for continuously operating said generators, and an electro-acoustic translating device: signal-transmitting means permanently connecting said generators with said translating device; output devices included in said generators, said transmitting means being responsive to said generators in accordance with sensitization of said outputdevices; and means for selectively sensitizing said output devices including a plurality of conductors, each conductor being connected with a plurality of'diiferentgenerator output devices for the common sensitization thereof.

3; In a musical instrument having a plurality of generators of frequencies respectively representing a musical scale, means for continuously operating said generators, and an electro acoustic translating device: signal-transmitting means permanently connecting said generators with said translating device; output devices included in said generators, said transmitting means being responsive to said generators in accordance with sensitization of said output devices; and means for selectively sensitizing said output devices including a plurality oi single-pole switches, each switch being connected with a plurality of output devices for different generators for the common sensitization thereof. 7

4. In a musical instrument having a plurality oi generators of frequencies respectively representing a musical scale, and means for continuously operating said generators: output devices for said generators, including a plurality of separate output devices for each of at least some of said generators; and means for selectively sensitizing said output devices, including a plurality of conductors each connected in common with a respective plurality substantially harmonically related, different generator output devices.

5. In a musical instrument having a plurality of generators of frequencies respectively representing a musical scale, and means for continuously operating said generators: output devices for said generators, including a plurality of separate output devices for each of at least some of said generators; and means for selectively sensitizing said output devices including a plurality of single-pole switching means, for different notes respectively, each connected in common with a respective plurality of substantially harmonically related, diflerent generators.

forming capacities with said tracks; a perma-' nent signal-transmitting circuit connecting said tracks and electrodes with said translating device; and means for impressing potentials selectively across said capacities, including a plurality of conductors each for the simultaneous impression of potentials across capacities associated with a plurality of different tracks.

7. The combination according to claim 1, further including time-delay means individually associated with each of said conductors.

8. The combination according to claim 5, further including time-delay means connected with each of said switches.

9. In a musical instrument having a plurality of generators of frequencies respectively representing a musical scale, and means for continuously operating said generators: output devices for said generators, including a plurality of separate output devices fo'r each of at least some of said generators; a plurality of means for grouping said output devices for combination of the outputs from devices associated with generators for consecutive notes; and a plurality of distinct means for grouping said devices for the simultaneous sensitization of devices associated with generators for harmonically related notes.

10, In a musical instrument having a plurality of generators of frequencies respectively representing a musical scale, and means for continuously operating said generators: output devices for said generators, including a plurality of separate output devices for each of at least some of said generators; a plurality of means for permanently grouping said devices for combination of the outputs from devices associated with generators for consecutive notes; and a pinrali'ty of means for permanently grouping said devices for the simultaneous sensitization of devices associated with generators for harmonically related notes.

11. The combination according to claim 9,-

wherein one of said two pluralities of grouping means is reactive and the other conductive.

12. The combination according to claim 9, wherein one of said two pluralities of grouping means is capacitive and the other conductive.

13. The combination according to' 'claim 9, wherein the first of said two pluralities of grouping means is capacitive and the second conductive.

'14. The combination according to claim 9, further including output control means associated with each of said first mentioned grouping means.

15. In a musical instrument including means providing an oscillatorily variable capacity, and an electro-acoustic translating device: a fixed condenser for transferring voltage from said variable capacity to said translating device, and an electrode forming simultaneously a plate of said condenser and a portion of saidcapacity-providing means.

16. In a musical instrument including a movable sound track, a pick-up therefor, and an electro-acoustic translating device: a fixed condenser for transferring oscillations from said pick-up to said translating device, and a member forming simultaneously a plate of saidcondenser and at least a portion of said pick-up.

17. In a musical instrument including a conductive sound track, a pick-up electrode in spaced relation thereto, and an electro-acoustlc translating device: a fixed condenser for transferring oscillations from said electrode to said translating device, said electrode forming one plate of said condenser.

18. In a musical instrument including means providing a plurality of mutually adjacent, oscillatorily variable capacities: electrodes form-- ing portions oi! said capacity-providing means, conductive means imth supporting and having capacities to said electrodes, and load means 19. In a musical instrument including means providing a plurality of mutually adjacent, oscillatorily variable capacities: a pair of conductive strips, electrodes forming portions of said capacity-providing means clamped between said strips at consecutive regions therealong, and dielectric means interposed between said strips and said electrodes.

* CHARLES '1. JACOBS. 

